pimd: Add pim_channel_oil_change_iif

Add a function that allows you to modify the channel oil's incoming
interface and to appropriately install/remove it from the kernel.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

6 files changed, 54 insertions, 35 deletions

diff --git a/pimd/pim_mroute.c b/pimd/pim_mroute.c
index b1c55c1f43..dc2db33f65 100644
--- a/pimd/pim_mroute.c
+++ b/pimd/pim_mroute.c
@@ -238,7 +238,8 @@ static int pim_mroute_msg_nocache(int fd, struct interface *ifp,
 		vif_index = pim_if_find_vifindex_by_ifindex(
 			pim_ifp->pim,
 			up->rpf.source_nexthop.interface->ifindex);
-		up->channel_oil->oil.mfcc_parent = vif_index;
+		pim_channel_oil_change_iif(pim_ifp->pim, up->channel_oil,
+					   vif_index, __PRETTY_FUNCTION__);
 	}
 	pim_register_join(up);
 
diff --git a/pimd/pim_oil.c b/pimd/pim_oil.c
index d4fc03e20c..d142934916 100644
--- a/pimd/pim_oil.c
+++ b/pimd/pim_oil.c
@@ -146,6 +146,43 @@ struct channel_oil *pim_find_channel_oil(struct pim_instance *pim,
 	return c_oil;
 }
 
+void pim_channel_oil_change_iif(struct pim_instance *pim,
+				struct channel_oil *c_oil,
+				int input_vif_index,
+				const char *name)
+{
+	int old_vif_index = c_oil->oil.mfcc_parent;
+	struct prefix_sg sg = {.src = c_oil->oil.mfcc_mcastgrp,
+			       .grp = c_oil->oil.mfcc_origin};
+
+	if (c_oil->oil.mfcc_parent == input_vif_index) {
+		if (PIM_DEBUG_MROUTE_DETAIL)
+			zlog_debug("%s(%s): Existing channel oil %pSG4 already using %d as IIF",
+				   __PRETTY_FUNCTION__, name, &sg,
+				   input_vif_index);
+
+		return;
+	}
+
+	if (PIM_DEBUG_MROUTE_DETAIL)
+		zlog_debug("%s(%s): Changing channel oil %pSG4 IIF from %d to %d installed: %d",
+			   __PRETTY_FUNCTION__, name, &sg,
+			   c_oil->oil.mfcc_parent, input_vif_index,
+			   c_oil->installed);
+
+	c_oil->oil.mfcc_parent = input_vif_index;
+	if (c_oil->installed) {
+		if (input_vif_index == MAXVIFS)
+			pim_mroute_del(c_oil, name);
+		else
+			pim_mroute_add(c_oil, name);
+	} else
+		if (old_vif_index == MAXVIFS)
+			pim_mroute_add(c_oil, name);
+
+	return;
+}
+
 struct channel_oil *pim_channel_oil_add(struct pim_instance *pim,
 					struct prefix_sg *sg,
 					int input_vif_index, const char *name)
@@ -164,7 +201,8 @@ struct channel_oil *pim_channel_oil_add(struct pim_instance *pim,
 					c_oil->oil.mfcc_parent,
 					input_vif_index);
 		}
-		c_oil->oil.mfcc_parent = input_vif_index;
+		pim_channel_oil_change_iif(pim, c_oil, input_vif_index,
+					   name);
 		++c_oil->oil_ref_count;
 		/* channel might be present prior to upstream */
 		c_oil->up = pim_upstream_find(pim, sg);
diff --git a/pimd/pim_oil.h b/pimd/pim_oil.h
index 485299196d..319a1c91a3 100644
--- a/pimd/pim_oil.h
+++ b/pimd/pim_oil.h
@@ -114,6 +114,9 @@ struct channel_oil *pim_find_channel_oil(struct pim_instance *pim,
 struct channel_oil *pim_channel_oil_add(struct pim_instance *pim,
 					struct prefix_sg *sg,
 					int input_vif_index, const char *name);
+void pim_channel_oil_change_iif(struct pim_instance *pim,
+				struct channel_oil *c_oil, int input_vif_index,
+				const char *name);
 void pim_channel_oil_del(struct channel_oil *c_oil, const char *name);
 
 int pim_channel_add_oif(struct channel_oil *c_oil, struct interface *oif,
diff --git a/pimd/pim_rpf.c b/pimd/pim_rpf.c
index 7d263e99e3..357ad6ba46 100644
--- a/pimd/pim_rpf.c
+++ b/pimd/pim_rpf.c
@@ -307,11 +307,11 @@ void pim_upstream_rpf_clear(struct pim_instance *pim,
 			    struct pim_upstream *up)
 {
 	if (up->rpf.source_nexthop.interface) {
-		if (up->channel_oil) {
-			up->channel_oil->oil.mfcc_parent = MAXVIFS;
-			pim_mroute_del(up->channel_oil, __PRETTY_FUNCTION__);
+		if (up->channel_oil)
+			pim_channel_oil_change_iif(pim, up->channel_oil,
+						   MAXVIFS,
+						   __PRETTY_FUNCTION__);
 
-		}
 		pim_upstream_switch(pim, up, PIM_UPSTREAM_NOTJOINED);
 		up->rpf.source_nexthop.interface = NULL;
 		up->rpf.source_nexthop.mrib_nexthop_addr.u.prefix4.s_addr =
diff --git a/pimd/pim_static.c b/pimd/pim_static.c
index 62c3216e86..e3138360c8 100644
--- a/pimd/pim_static.c
+++ b/pimd/pim_static.c
@@ -138,7 +138,9 @@ int pim_static_add(struct pim_instance *pim, struct interface *iif,
 			} else {
 				/* input interface changed */
 				s_route->iif = iif_index;
-				s_route->c_oil.oil.mfcc_parent = iif_index;
+				pim_channel_oil_change_iif(pim, &s_route->c_oil,
+							   iif_index,
+							   __PRETTY_FUNCTION__);
 
 #ifdef PIM_ENFORCE_LOOPFREE_MFC
 				/* check to make sure the new input was not an
diff --git a/pimd/pim_zebra.c b/pimd/pim_zebra.c
index 675e81f5a1..3b93dd2b3c 100644
--- a/pimd/pim_zebra.c
+++ b/pimd/pim_zebra.c
@@ -601,7 +601,6 @@ void pim_scan_individual_oil(struct channel_oil *c_oil, int in_vif_index)
 {
 	struct in_addr vif_source;
 	int input_iface_vif_index;
-	int old_vif_index;
 
 	pim_rp_set_upstream_addr(c_oil->pim, &vif_source,
 				      c_oil->oil.mfcc_origin,
@@ -701,33 +700,9 @@ void pim_scan_individual_oil(struct channel_oil *c_oil, int in_vif_index)
 	}
 
 	/* update iif vif_index */
-	old_vif_index = c_oil->oil.mfcc_parent;
-	c_oil->oil.mfcc_parent = input_iface_vif_index;
-
-	/* update kernel multicast forwarding cache (MFC) */
-	if (pim_mroute_add(c_oil, __PRETTY_FUNCTION__)) {
-		if (PIM_DEBUG_MROUTE) {
-			/* just log warning */
-			struct interface *old_iif = pim_if_find_by_vif_index(
-				c_oil->pim, old_vif_index);
-			struct interface *new_iif = pim_if_find_by_vif_index(
-				c_oil->pim, input_iface_vif_index);
-			char source_str[INET_ADDRSTRLEN];
-			char group_str[INET_ADDRSTRLEN];
-			pim_inet4_dump("<source?>", c_oil->oil.mfcc_origin,
-				       source_str, sizeof(source_str));
-			pim_inet4_dump("<group?>", c_oil->oil.mfcc_mcastgrp,
-				       group_str, sizeof(group_str));
-			zlog_debug(
-				"%s %s: (S,G)=(%s,%s) failure updating input interface from %s vif_index=%d to %s vif_index=%d",
-				__FILE__, __PRETTY_FUNCTION__, source_str,
-				group_str,
-				old_iif ? old_iif->name : "<old_iif?>",
-				c_oil->oil.mfcc_parent,
-				new_iif ? new_iif->name : "<new_iif?>",
-				input_iface_vif_index);
-		}
-	}
+	pim_channel_oil_change_iif(c_oil->pim, c_oil, input_iface_vif_index,
+				   __PRETTY_FUNCTION__);
+	pim_mroute_add(c_oil, __PRETTY_FUNCTION__);
 }
 
 void pim_scan_oil(struct pim_instance *pim)